Performance evaluation of reconfigurable ALU based on DG-CNTFET transistors

Arithmetic and Logic Unit represent the core of all microprocessors. It performs arithmetic and logical operations. ALU is getting more complex and smaller to make more efficient circuits. This paper describes simple ALU but contains the essentials functions. It is a reconfigurable ALU based on double gate carbon nanotube field effect transistors (DG-CNTFETs). The proposed ALU is designed for one bit operation and can realize three functions (NAND, OR and FULL ADDER). We will demonstrate the benefit of designing a reconfigurable ALU using a compact physical model of DG-CNTFET transistor. First, an explanation of controllable polarity transistor is given. Then a dynamically reconfigurable circuit and 3-function ALU based on a (DG-CNTFET) are described, simulated and analyzed. Finally an overall performance comparison in term of average Power Consumption and delay with CMOS LUT is done. Results shows that this 3-functions ALU have PDP, power and delay better than all 1-bit CMOS full adders, 44% reduction in the consumption and 12% enhancement in delay time.